title: Effects of isobutyrate on rumen fermentation, urinary excretion of purine derivatives and digestibility in steers.
abstract: The objective of this study was to evaluate the effects of isobutyrate supplementations on rumen fermentation, urinary excretion of purine derivatives and feed digestibility in steers. Eight ruminally cannulated Simmental steers were used in a replicated 4 x 4 Latin square experiment. On DM basis, diet consisted of 60% corn stover and 40% concentrate. Dry matter intake (averaged 9 kg/d) was restricted to 90% of ad libitum intake. The four treatment groups received a daily dose of 0 (control), 8.4, 16.8 or 25.2 g isobutyrate per steer. With increasing isobutyrate supplementation total VFA concentration (range 64.2-74.0 mM) was significantly enhanced. The ratio of acetate to propionate (range 2.72-4.25) was also significantly increased due to the increase in actate production and decrease in propionate production. With increasing isobutyrate supplementation the ruminal degradation of NDF from corn stover was improved but the CP degradability of soybean meal was decreased. Furthermore, the isobutyrate supplementation caused a significantly increased urinary excretion of purine derivatives. Similarly, digestibilities of OM, NDF and CP in the total tract were significantly increased. The present results indicate that dietary supplementation with isobutyrate improved rumen fermentation and feed digestion in beef cattle in a dose-dependent manner. According to the conditions of this experiment, the optimum daily dose of isobutyrate was about 16.8 g/animal.
authors.affiliation: College of Animal Sciences and Veterinary Medicines, Shanxi Agricultural University, Taigu, Shanxi, PR China. liuqiangabc@163.com
authors.forename: Qiang
authors.initials: Q
authors.lastname: Liu
authors.forename: Cong
authors.initials: C
authors.lastname: Wang
authors.forename: YingXiang
authors.initials: Y
authors.lastname: Huang
authors.forename: KuanHu
authors.initials: K
authors.lastname: Dong
authors.forename: WenZu
authors.initials: W
authors.lastname: Yang
authors.forename: Hao
authors.initials: H
authors.lastname: Wang
mesh_terms: D000821:Animal Feed; D000824:Animal Nutritional Physiological Phenomena / Q000502:physiology; D000818:Animals; D002087:Butyrates / Q000008:administration & dosage / Q000494:pharmacology*; D002417:Cattle / Q000378:metabolism*; D004063:Digestion / Q000187:drug effects* / Q000502:physiology; D004305:Dose-Response Relationship, Drug; D005285:Fermentation / Q000187:drug effects* / Q000502:physiology; D058610:Isobutyrates; D008297:Male; D011687:Purines / Q000652:urine*; D011897:Random Allocation; D012417:Rumen / Q000737:chemistry / Q000378:metabolism* / Q000382:microbiology
chemical_list: D002087:Butyrates; D058610:Isobutyrates; D011687:Purines; C020380:isobutyric acid; C030985:purine